Feeding means for power hacksaw-machines.



A. RASMUSSEN. FEEDING MEANS FOR POWER HAGKSAW MACHINES APPLICATION FILED JULY 29, 1910.

Patented: May 7,1912;

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FEEDING MEANS FOR POWER HAOKSAW MACHINES.

APPLICATION FILED JULY 29, 1910.

Patented May 7, 1912.

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[a (Us 6153 moving through its non-cutting "stroke, the

'UNITED STATES PATENT OFFICE.

ANDREW nasmnssnn, or moms JUNCTION, Wisconsin.

FEEDING nuns non POWER Hacksaw-momma Specification of Letters l'atent. Application filed July 29, 1910. Serial No. 574,448.

To all whom it may concern: Be it known thatI, Anonnw RAsMUssEn a citizen of theUnited States, and a resident of Racine Junction, inthe county of Racine and State of Wisconsin, have invented certain new and useful.Improvements in Feeding Means for Power Hacksaw-Machines; and I do hereby declare that the following is a full, clear,'and exact description thereof, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part ofthis specification.

This invention relates to improvements in feeding means for power hack saw machines of that kind which releases .the saw blade from the work during the non-cutting stroke of the saw so as to avoid wear on the. saw and to permit the saw to cool during its non-cutting stroke. g

The object of the invention is to provide an improved feeding device of this character which is adaptable to work of all kinds, in such manner as to regulate the feed of the saw to correspond with the char.- acter and hardness of the material being sawed; to provide a feed device which will press .the saw gently to the Work at the be-.

ginning of its cutting stroke and avoid bringing the saw abruptly to the work in a manner to injure its saw blade, and to provide a feed device which will produce a clean. out, free from roughness and. unevenness.

Other objects. of the invention are'to r0-. vlde a s1m'ple, inexpensive and compact eed device, which may be readily and economically adapted to any power hack saw ma- -chi'ne.-

teeth of the sawtraveling backwardly the "non-cutting stroke thereof in substantially the same path in which they advanced ereby, arranged to effect the in the last cutting stroke,so that when feed pressure, either spring or weight applied, is

Patented May 7, 1912.

rought to bear upon the saw, said saw is moved into contact with the work gently and without such shock as will tend to injure the teeth. Moreover, inasmuch as the saw is not lifted a distance away from the bottom of the cut at the.end of. its cutting stroke, there is no tendency for the teeth of the saw to roughen thesides of the saw cut, is truewhere the saw-is lifted a substantial distance at theend of its cutting stroke. Thereby the cut ends of the work are left: smooth and free from roughness. The feed pressure may be exerted on the saw to press it to its work in any suitable manner, and means are provided, operative at the end of the cuttingstroke of the saw, to release said ressure, which releasing means may bee ected by counterbalancing the saw guide and support, as stated.

The invention consists in the matters hereinafter set forth and more particularly pointed out in the appended claims.

, In the drawings,Figure 1 is a'sideele- .vation of a power hack saw machine showing my invention applied thereto. Fig. 2' is a plan view thereof. Fig. 3 ls-a hOIl zontal section on the line 3-3 ofFig. 1.

Fig. 4 is a vertical section on the line 44=.-

of Fig. 3. Fig. 5 is a side elevationof apower hack saw. machine, showing a modification of the feeding device.

The hack saw machine may, so far asits general features of construction are concerned, follow any type or design desired.

It comprises as herein shown a horizontal table 6' supported "on legs 7, a vertically swinging sa'w frame guide and support 8 that is pivotally connected at its rear end to the main driving shaft 9 of the machine,

and slidingly supports at its forward end the usual saw frame 10 between the legs of whichisstretched the sawblade 11. The

guiding connection between the saw frame and the vertically movable ide and 'sup port 8 consists, as shown, 0 a lateral lug or extension 12 on the saw frame which has guiding engagement with said support 8, as most. clearly shown in Fig. 2; The reclprocating saw frame 10 is connected by a pitmam 13 with an eccentrically located stud 14 on a crank disk-15 of the shaft 9 wherebythe saw frame is reciprocated. The said shaft 9 is mounted in laterally se arated bearings 16, which rise fromte rear end of-the table 6 and the shaft is provided at one end with a belt pulley 17. The machine is provided at the saw end thereof with the usual stationary and movable jaws 20, 21 of a work holding vise, which is operated by theusual screw 22.

The saw frame support and guide are normally counterbalanced, when no feed pressure is exerted thereon, which occurs during the non-cutting stroke of the saw, so

- that at this time the saw blades will not bear with any pressure a ainst the bottom of the saw cut in the wor Such counterbalancing effect may-be produced in any suitable or preferredmanner, depending upon the design of the machine or the selection of the designer. As herein shown such counterbalancing effect is produced by gravity, the said saw frame support and guide being provided with the rearwardly extend- 1n g arm 25, which may be made integral wlth, and extend rearwardly from the bearingf sleeve orv hub 26 of said guide, and a counterbalancing weight 27 is slidingly mounted on said arm and is adapted to be locked thereto, as by the set screw 28.

The means for pressing the saw to its work'during the cutting stroke thereof embraces means for eflec'ting a downward ull on the saw frame support and guide, w ich downward pull is regulated in its force or efiect to adapt it to work of 'diflerent char- ."aeters, and said feeding means embraces means for tripping or releasing the pressure means at the'end of the cutting stroke of the saw so as to place the support and guide under the influence of the counterbalancing means described. The s ecific form of mechanism which I have erein shown for effecting this result is made as follows: 34

designates a bracket which depends from and is attached, as by means of the screw bolt 35, to the under side of the table 6.

' Said bracket is provided with a vertical way 36 in which slides a ratchet bar 37 that isadapted to be connected, as by the link 39,

' to the saw frame sup ort and guide or diteeth'38 ofthe ratchet bar 37.

. that is mounted in thelower en Shown said dog is located-on the under side 'of a recessed portion of the arm 44 and is slotted to receive a guide bolt 46 that extends downwardly through the arm 44.-

The dog is held up against the ratchet teeth by a sp ral, expansive sprin 47 that is interposed between the rear em? of the dog and a shoulder 48 on the arm 44 of said lever.

. In order that the dog may be retracted s herein to permit the ratchet bar to be moved up wardly past the same, for a purpose hereinafter described, the said guide bolt 46 is shown as rotatively mounted in the arm 44 and as provided at its lower end with an eccentric disk 50 arranged between the dog and a collar 51 attached to thelo-wer end of the bolt. Said disk bears at its rear side against an abutment on the dog, as the screw 52. The bolt 46 is provided at its upper end with a hand piece 53 by which it may be rotated. The slot in the dog through which the bolt 46 passes is of such length that the spring 47 normally holds the dog pressed 'firmly against its ratchet teeth, while permitting the dog to yield backwardly to engage a next higher tooth of the ratchet bar 37 when the forward end of the lever carrying the dog is raised, as by the means hereinafter set forth. The eccentric disk 50 is so disposed on the bolt 46 as to force the dog backwardly, when the bolt is turned a half rotation from the position shown in the drawings, such distance as-to release the dog from the ratchet teeth, and thereby permit the ratchet bar to be moved upwardly past the dog. The higher part of the eccentric disk may be slightly flattened or notched to engage the screw 52 when turned into position to retract the dogso as to automatically lock the dog in its retracted position.

The longer arm 55 of the lever 40 extends upwardly and rearwardly from its pivot 41,

through a suitable slot in the table 6, and carries at its u per end a bearing roller 56 that is arranged beneath, and is adapted to engage the dperiphery of, a cam or an eccentric 58 fixe to and rotating with the power shaft 9. The periphery of the cam 58 is shown as divided into two substantially equal parts, to wit, a higher part a and a lower part 6 connected by the oblique or cam portions 0. The longer arm of said lever 40 is normally pressed toward or against the'periphery of the cam or eccentric, by means permitting said longer arm to yield backwardly away from the axis of the cam. This may be effected either through the action of a spring or weight, and such pressure may be ap lied in any suitable manner-to the lever, epending upon its position in the machine, or upon the selection of the designer. As herein shown the lever arm 55 is pressed toward the cam by means of a spiral spring 60 which is backed by a screw 61 screw-threaded into a bracket 62 that is fixed to the rear le ofthe machine. Said screw constitutes a so means for adjusting the pressure by which the lever is pressed toward the cam and the screw may be locked in adjusted position by means of a jam nut 63. p

The operation of the feeding device described is as follows: When the lower portion I; of the periphery of the cam 58 is actuating and supporting lever 40, the spring 60 acts against the longer arm of said lever in a direction to depress the shorter arm thereof and the dog carried thereby so as to efiect a downward pull, through the ratchet bar 37 and link 39, on the saw frame guide and support, and thereby press or force the saw to its work. i This pressure is continued throughout one-half the rotation of the cam and, therefore, throughout the cutting stroke of the saw. At, the endof the cutting stroke of the sawthe higher part a of the periphery of the cam engages the bearing roller 56 of the dog supportiiig and actuating lever 40, and the longer arm of the lever is forced away from the axis of the cam, thereby raising the shorter arm of the lever and the dog carried thereby, so as to relieve the feed ressure on the saw, and to permit the saw rame support and guide to be counterbalanced. Such release of the feed pressure occurs at the end of the cutting stroke of the saw, and the dog is held-away from the ratchet and the parts are counterbalanced throu' bout the half rotation of the cam in which t e bearing roller 56 is riding over the higher part a of the cam, which oecurs during the non-cutting stroke of the saw. Thedog 45 willfnot, however, necessarily engage overlthe next higher tooth in each swinging movement of the dog actuat ing lever,--but will be raised high enough from the ratchet tooth last engaged to release the feed pressure.

It wlll'be observed that when the higher 7 part a of the en ages the bearing roller 56 of the dog actuating lever 40, it releases the, engagement of the dog from the ratchet teeth 38, and that when such release is efiected the saw frame guide and su port is counterbalanced, so that during t e noncutting stroke of the saw the saw will not ress against the bottom of the saw, cut. either willthe' saw be raised substantially above the bottom of the saw cut, but will a pass back thereover in substantially the same pathin which it moved .during the cutting stroke. For instance, when operating on hard material the spring 60, or other feed pressure element, may not press the bearmg roller 56 of the dog actuating lever entirely against or in contact with the lower portion of the cam 58, and in such'case when the lever is swung back, through the action of the higher portion of the cam or eccentric on said bearing roller, the shorter arm of the lever will not be raised sufficiently to carry the dog into engagement with the next higher ratchet tooth, but the feed pressure in the next succeeding cutting stroke ofthe 1 saw will be transmitted through the same ratchet tooth as that which transmitted the I feed pressure in the last cutting stroke of the saw. When working on softer maiterials,

however, the cut of the saw may be sufliciently ra id to permit the ratchet bar- 37 to move ownwardly, during each cutting stroke of the saw a distance equal to the space between ad acent ratchet teeth, and

in this event the movement of the dog actuating lever" in each operation thereof may be sufliclent to step the dog from one tooth to the next higher tooth in each upward movement of the dog. After the saw has severed the work and reaches its lowermost position, the dog igruide bolt 46 is rotated' to release the dog cm the ratchet teeth so that the saw frame guide and support may be raised to place another piece of work under the saw.

In Fig. 5 is showna. modified form of the ratchet element for advancing the feed pressure as 'the saw cuts into its work. The ratchet element shown in Fig. 5 has ,the

"form of a ratchet disk 65. which is rotatively mounted on a pin 66 that is mounted in a bracket 67 which is attached to and depends from the table 6. The ratchet teeth 68 of said disk 65 are adapted for engagement by the dog in the same general manner as the ratchet teeth38 of thebar 37 before described. Said ratchet disk is herein shown as connected to the saw frame support and guide through the means of a sprocket chain 70 attached at its upper end to a lug 71 on the said support and guide and adapted to engage sprocket teeth 72 formed on a drum which rotates with the ratchet wheel or disk '65. The sprocket chain is herein shown as continued past-the sprocket teeth and is trained over an idler pulley 74 that is mounted in a bracket 75 "depending from the table 6, and the free end of said chain,.heyond said idler, is provided with a weight 76. The said weight serves to maintain the chain 7 O taut and alsopre-' vents backward rotation of the ratchet wheel or disk when the dog is moved up wardly over' the ratchet teeth for engagement'with a next upper-tooth' The backward rotation of the ratchet disk may be prevented by other means, and the connection between the ratchet disk and saw frame guide and support may be OthGI'WlSB efected. V

- It will be obvious that the feed pressure exerted by both forms of feed device shown is a yielding pressure, and 18 also a regulabottom of the saw cut at the end of its cutting stroke, it is brought gently and without shock against the work in the beginning of the next succeeding cutting stroke, so that there is no liability of-injuring thesaw I teeth. Furthermore, by reason of the fact that the saw is not raised a distance from the bottom of the saw cut, the saw teeth will not mar or roughen the sides of the saw cut during its passage therethrough in its noncutting stroke, such as occurs when the saw is raised a substantial distance from the bottom of the saw out.

a reciprocating saw frame and a vertically movable supporting guide, of means independent of the weight of said frame andguide for exerting feed pressure on the saw during its cutting stroke, and means for re-' leasing said feed pressure during the noncutting stroke of the saw, whereby the teeth pendent of the weight of said frame and of the saw on the non-cutting stroke thereof will move in a line defined by said teeth at the endv of the cutting stroke. I

2. Feeding means for power hack saw machines, comprising in combination with a reciprocating saw frame and a vertically movable supporting guide, means independent of the weight of said frame and guide for exerting a yielding feed pressure on the saw during the cutting stroke thereof, and means for releasing the feed pressure at the end of the cutting stroke, wherebythe teeth of the saw on the non-cutting stroke thereof will move in a line defined by said teeth at the end of the cutting stroke.

3. Feeding means for power hack saw machines, comprising in combination witha reciprocating saw frame and a vertically movable supporting guide, of means indeguide for exerting feed pressure on the saw during its cutting stroke, means for counterbalancing the saw frame and guide and means for releasing said feedpress'ure at the end of the cuttlng stroke, whereby the teeth of the saw. on the non-cutting stroke thereof will movein a line defined by said teeth at the end of the cutting stroke. I

4. Feeding means for power hack saw machines, comprising in combination with a '7 reciprocating saw frame and a vertically movable supporting guide, of means independent of the weight of said frame and guide for exerting feed pressure on the saw during its cutting stroke, means for regulating said pressure and means for releasing said feed pressure at the endof the cutting stroke, whereby the teeth of the saw on the 'to release the fee non-cutting stroke thereof will move in a line defined by said teeth at the end of the cutting stroke.

5. Feeding means for power hack saw machines comprising, in combination with the reciprocating saw' frame and its vertically movable supporting guide, means for exerting feed pressure on the saw during its cutting stroke, means for releasing said feed pressure, without lifting the saw, during the non-cuttin stroke of the saw, and means for releasing te' feed pressure means from thesaw constructed to permit the supporting guide and saw frame to be raised relatively to the pressure means;

6. Feeding means for power hack saw machines comprising, in combination with the reciprocating saw frame and its vertically movable supporting guide, a cam movable with the saw, a pivoted lever one arm of which is acted upon by said cam, a feed pressure device acted upon by the other arm chines comprising, in combination with the reciprocating saw frame and vertically movable supporting guide, of cam' controlled means for exertlng feed pressure on the saw during its cuttin stroke, embracing means ressure at the end of the cutting stroke, an means for counterbalancing the saw frame and support when the feed pressure is so released and operative throughout the non-cutting stroke of the saw.

8. Feeding means for power hack saw machines comprising, in combination with the reciprocating saw frame and its vertically movable sup orting guide, a ratchet connected to an movable with the supporting guide, a cam actuated lever, a dog on the lever to engage the ratchet during the cutting stroke of the saw to press the saw to its work, said cam releasing the dog from the ratchet at the end of the cutting stroke and means operating to counterbalance the saw frame and supporting guide when so released.

9. Feeding means for power hack saw machines comprising, in combination with the reciprocating saw frame and its vertically movable supporting guide, a ratchet connectedto and movable with the supportin guide, a spring controlled dog engaging said ratchet, a rotative cam, a swinging lever carrying the dog and havin a bearing engaging the cam, and arrang i during a part of the rotation of the cam to press the dog upon the ratchet, and during another part to release, the dog from the ratchet, and means to'counterbalance' the saw frame and guide whenthe dog is released from said ratchet.

- connected to and movable-with the supporting guide, a spring controlled dog engaging said ratchet, a rotative cam, a swinging lever carrying the dog and having a bearing engaging the cam, and arranged during a part of the rotation of the cam to press the dog upon the ratchet, and during another part to release the dog from the ratchet, means to counterbalance the saw frame and guide when the dog is released from said ratchet, and adjusting means acting on said lever to vary the feed pressure exerted therethrough on the saw.

11. Feeding means for power hack saw machines comprising, in combination with the reciprocatlng saw frame and its vertically movable supporting guide, a cam or eccentric movable with the saw,'a pivoted lever one arm of which is acted upon by the cam or eccentric, a ratchet movable with the supporting guide, a spring controlled dog carried by said lever for engagement with the ratchet, a guide bolt on the lever for the dog having means to retract the dog away from the ratchet, said cam or eccentric acting through the lever, the dog and ratchet during the cutting stroke of the saw to press the saw to its work, and to release the feed pressure at the end of the cutting stroke, and means for counterbalancing :the saw frame and guide when the feed pressure is so released and operative throughout the non-cutting stroke of the saw.

12. In a power hack saw machine, the combination of a .power shaft, a reciprocating s aw frame, a supporting guide for the frame pivoted to the power shaft, operative connections between the power shaft and saw frame to reciprocate the latter, means to counterbalance the saw frame and its guide, means independent of the 'weightof said frame and guide for exerting feed pressure on the saw during its cutting stroke, and means for releasing said feed pressure at the end of the cutting stroke, whereby the teeth of the saw on the non-cutting stroke "thereof willmove'in a line defined by said teeth at the end of the cutting stroke.

13. The combination, in a power hack'saw machine, of a power ,shaft, a reciprocating saw frame, a supporting guide for the frame pivoted to the power shaft, operative connections between the power shaft and saw frame to reciprocate the latter, a cam or .eccentric fixed to the power shaft, a pivoted lever engaging said cam or eccentric, feed pressure means actuated by said lever and means to press the lever against the cam, all

arranged to exerta yielding feed pressure on the saw during the cutting stroke thereof and to release said feed pressure without substantially lifting the saw during the noncutting stroke of the saw.

14. The combination, in a power hack saw machine, of a power shaft, a reciprocating saw frame, a supporting guide for the frame pivoted to the power shaft, operative connections between the power shaft and saw frameto reciprocate the latter, means to counterbalance the saw frame and its-guide during the non-cutting stroke of the saw, a cam or eccentric fixed to the power shaft, a pivoted lever engaging said cam or eccentric, feed pressure means actuated by said lever arranged to exert feed pressure on the saw during the cutting stroke thereof and 

